annotate src/scheme/task.scm @ 0:bf79fb79ee13

Initial Mercurial check in.

;;; task related utilities
(import "samer.tools.*")


(define task (macro body `(SilkTask. (lambda () ,@body))))

;;; convert a CompoundTask to a Scheme list
(define (tasks->list tasks)
	(define L ())
	(define (list-it it)
		(if (.more it) (begin
			(set! L (append L (list (.next it))))
		(list-it it))))
	(list-it (.iterator tasks))
	L
)

;;; create and access main task list

(define _thread null)
(define _tasklist_stack ())

(define (start) (exec _thread "start"))
(define (stop)  (exec _thread "stop"))
(define (thread) _thread)

;;; creates a task list/thread if none exists, returns a task list
(define (tasks)
	(if (null? _tasklist_stack)
		(let ((t (CompoundTask.)))
			(set! _thread (RThread. t))
			(push-tasklist t)
			t
		)
		(first _tasklist_stack)
	)
)

(define (push-tasklist t)
  (set! _tasklist_stack (cons t _tasklist_stack)))

(define (pop-tasklist)
  (let ((t (first _tasklist_stack)))
    (set! _tasklist_stack (rest _tasklist_stack))
	 t))

(define with-tasks (macro (tasks . body)
	`(begin
		(push-tasklist ,tasks)
		(tryCatch
			(let ((a (begin . ,body))) (pop-tasklist) a)
			(lambda (ex) (pop-tasklist) (throw ex))))))

; add task to current task list
(define (addtask t) (.addTask (tasks) t) t)
(define (removetask t) (.removeTask (tasks) t) t)
(define-method (add (t Task)) (.addTask (tasks) t) t)
(define-method (addafter (a Task) (t Task)) (.addTaskAfter (tasks) t a) t)
(define-method (remove (t Task)) (.removeTask (tasks) t) t)

; add multiple tasks to current task list
(define (addtasks . t)
	(for-each (lambda (t) (.addTask (tasks) t)) t)
	(tasks) )

(define-method (pr-tasks) (print (tasks->list (tasks))))
(define-method (view-tasks) (view-tasks (tasks)))
(define-method (view-tasks tasks) (view-list (tasks->list tasks) "Tasks"))
(define-method (task-ref (n Integer)) (list-ref (tasks->list (tasks)) n))
(define-method (task-ref tasks (n Integer)) (list-ref (tasks->list tasks) n))

(define (switch task) (SwitchTask. task))

;;; Create a subrate task and a UI for the subrate factor
;;; !! need to dispose of VInteger when task is disposed.
(define (sub n task)
	(define vn (VInteger. "subfactor" n))
	(define subt (SubrateTask. n task))
	(on-change vn (.setFactor subt (.value$ vn)))
	(.value$ vn n) (.changed vn)
	subt
)

(define (seq . tasks)
	(define c (CompoundTask.))
	(for-each (lambda (t) (.addTask c t)) tasks)
	c)